From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D128CA9EAF for ; Thu, 24 Oct 2019 22:38:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6C15621D7F for ; Thu, 24 Oct 2019 22:38:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731543AbfJXWiS (ORCPT ); Thu, 24 Oct 2019 18:38:18 -0400 Received: from foss.arm.com ([217.140.110.172]:60508 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731152AbfJXWiR (ORCPT ); Thu, 24 Oct 2019 18:38:17 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 005F128; Thu, 24 Oct 2019 15:38:17 -0700 (PDT) Received: from [10.37.9.28] (unknown [10.37.9.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6EA7F3F718; Thu, 24 Oct 2019 15:38:15 -0700 (PDT) Subject: Re: [PATCH v9 02/12] kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils To: cristian.marussi@arm.com, linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org, shuah@kernel.org Cc: amit.kachhap@arm.com, andreyknvl@google.com, dave.martin@arm.com References: <20191009120459.21805-1-cristian.marussi@arm.com> <20191009120459.21805-3-cristian.marussi@arm.com> From: Suzuki K Poulose Message-ID: Date: Thu, 24 Oct 2019 23:41:50 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20191009120459.21805-3-cristian.marussi@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Hi Cristian, On 10/09/2019 01:04 PM, Cristian Marussi wrote: > Add some arm64/signal specific boilerplate and utility code to help > further testcases' development. > > Introduce also one simple testcase mangle_pstate_invalid_compat_toggle > and some related helpers: it is a simple mangle testcase which messes > with the ucontext_t from within the signal handler, trying to toggle > PSTATE state bits to switch the system between 32bit/64bit execution > state. Expects SIGSEGV on test PASS. > > Reviewed-by: Dave Martin > Signed-off-by: Cristian Marussi [...] > + > +#define get_regval(regname, out) \ > +{ \ > + asm volatile("mrs %0, " __stringify(regname) \ > + : "=r" (out) \ > + : \ > + : "memory"); \ > +} > + > +/* Regs encoding and masks naming copied in from sysreg.h */ > +#define SYS_ID_AA64MMFR1_EL1 S3_0_C0_C7_1 /* MRS Emulated */ > +#define SYS_ID_AA64MMFR2_EL1 S3_0_C0_C7_2 /* MRS Emulated */ > +#define ID_AA64MMFR1_PAN_SHIFT 20 > +#define ID_AA64MMFR2_UAO_SHIFT 4 > + > +/* Local Helpers */ > +#define ID_AA64MMFR1_EL1_PAN_SUPPORTED(val) \ > + (!!((val) & (0xfUL << ID_AA64MMFR1_PAN_SHIFT))) > +#define ID_AA64MMFR2_EL1_UAO_SUPPORTED(val) \ > + (!!((val) & (0xfUL << ID_AA64MMFR2_UAO_SHIFT))) > + > +/* > + * Feature flags used in tdescr.feats_required to specify > + * any feature by the test > + */ > +enum { > + FSSBS_BIT, > + FPAN_BIT, > + FUAO_BIT, > + FMAX_END > +}; > + > +#define FEAT_SSBS (1UL << FSSBS_BIT) > +#define FEAT_PAN (1UL << FPAN_BIT) > +#define FEAT_UAO (1UL << FUAO_BIT) > + [...] > +static int test_init(struct tdescr *td) > +{ > + td->minsigstksz = getauxval(AT_MINSIGSTKSZ); > + if (!td->minsigstksz) > + td->minsigstksz = MINSIGSTKSZ; > + fprintf(stderr, "Detected MINSTKSIGSZ:%d\n", td->minsigstksz); > + > + if (td->feats_required) { > + td->feats_supported = 0; > + /* > + * Checking for CPU required features using both the > + * auxval and the arm64 MRS Emulation to read sysregs. > + */ > + if (getauxval(AT_HWCAP) & HWCAP_SSBS) > + td->feats_supported |= FEAT_SSBS; > + if (getauxval(AT_HWCAP) & HWCAP_CPUID) { > + uint64_t val = 0; > + > + /* Uses MRS emulation to check capability */ > + get_regval(SYS_ID_AA64MMFR1_EL1, val); > + if (ID_AA64MMFR1_EL1_PAN_SUPPORTED(val)) > + td->feats_supported |= FEAT_PAN; > + /* Uses MRS emulation to check capability */ > + get_regval(SYS_ID_AA64MMFR2_EL1, val); > + if (ID_AA64MMFR2_EL1_UAO_SUPPORTED(val)) > + td->feats_supported |= FEAT_UAO; As discussed, these fields are never exposed to userspace via mrs. So you may as well drop these features. Cheers Suzuki